John m



J. M. DEXTER.

Lamp.

No. "236,937; .Paten'ted Jan. 25,1881.

N. PETERS, PHOTO-LITHCIBRAPHER, WASHINGTON. D C- UNITED STATES PATENTOFFICE.

JOHN M. DEXTER, 0E ELMIRA, NEW YORK.

LAMP.

SPECIFICATION formingpart of Letters Patent No. 236,937, dated January25, 1881.

Application filed October 8, 1879.

To all whom it may concern:

Be it known that I, JOHN M. DEXTER, of Elmira, in the county of Ohemungand State of New York, have invented certain new and useful Improvementsin Lamps; and I do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same, referencebeing had to the accompanying drawings, and to letters of referencemarked thereon, which form part of this specification.

My invention is a lamp constructed, as fully described hereinafter, soas to avoid the danger of breakage incident to ordinary constructions,prevent oil from passing to the outside of the reservoir, the dangerofthe burner becoming loose, and to facilitate the manufacture.

In the drawings, Figure 1 is a sectional elevation of suiflcient of alamp to show my improvements. Fig. 2 is'a perspective view, and Fig. 3 asectional view, showing the ordinary mode of securing the burner.

In the construction of ordinary lamps havin g reservoirs of vitreousmaterials, it has been common to providethe reservoir A with anupwardly-projecting neck, I), to which is cemented a metal cap orcollar, H, having an internal-threaded socket adapted to receive thethreaded projection c of the burner I. @wing to the projection of theneck above the reservoir it can be readily struck, and is frequentlybroken in this manner, this being one of the common causes of thebreaking of such lamps. I remedy this by forming the reservoir with aninternal neckthat is, with a neck, I), projectingdownward into thereservoir, instead of extendin g above itso that instead of being themost exposed it is the best protected part of the'lamp.

Another objection to lamps having vitreous reservoirs is the liabilityof the oil to pass downward over the outside of the reservoir, flowingeither from the joint between the latter and the cap or collar H,dripping from the wick above the wick-tube, or fromthe spout of thefilling -.vessel. Attempts have been made to obviate this by forming thecaps or collars with basins and grooves to IuQGiVB the oil dripping fromthe burner, and carrying it back into the reservoir; but it will beapparent that in such case there is a joint between the cap and theburner, outside of the dripopening, through which the oil may exude.

Thus, if the drip-opening was at at, Fig. 3, the outside joint at ywould permit the oil splashed up in moving the lamp to escape when therewas any internal pressure or any capillary action. To avoid suchobjections 1t has been proposed to make the body of a lamp with alateral flange at the top, forming an oil-receptacle but it is notpossible to form such flange in the same piece with the vitreous body,and if made of other material the outside joint would be attended withthe same objections as when a cap is used. Moreover, the outsideflanges, even it this could be made, would be so exposed as to bequickly broken. I obviate these objections by forming threads cin theneck I), and by making channels E across such threads, and by depressingthe top of the reservoir to form a basin, B, the inclined bottom ofwhich directs all oil spilled or flowing in any way onto the top of thereservoir to the channels E, through which it flows into the reservoir.

It will be seen that by forming the threads 0 in the neck there can beno joint outside of such threads, as heretofore, communicating with thereservoir, and affording a means of exit, that the possibility of theburner dropping ott' from loosening of the attachment, as when using acemented cap, H, is absolutely prevented, and that the basin B can bereadily formed during the ordinary manufacture of the lamp, and withoutpresenting any portion of the lamp in an exposed situation.

I am aware that it is not new to form an oilchannel across the threadsand communicating with drip-cup; but I know of no instance Where suchchannels are formed in the outside joint, connecting the metallic andvitreous portions of the lamp.

I claim The lamp-reservoir shown and described, consisting of the bowlA, having the basin B extending downward into the body of the bowl, andprovided with a threaded neck extending downward from the basin, saidneck having channels E crossing the threads, substantially as set forth.

In testimony that I claim the foregoing I have hereunto set my hand andseal this 3d day of October, 1879.

JNO. M. DEXTER. 1.. s.]

Witnesses:

\ HENRY A. DEXTER,

ELISHA G. BALDWIN.

